Geologic time periods

This category is also used for geologic time and geologic age.
Subtopics:
Phanerozoic (8 items)
Precambrian (2 items)

Results listed by similarity [list alphabetically]
Precambrian basement structure map of the continental United States-an interpretation of geologic and aeromagnetic data

Principal basement structures formed during the Precambrian in the continental United States based on interpretation of regional aeromagnetic anomaly data of North America.

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Complete analytical data for Jurassic igneous rocks in the Bald Mountain mining district, Nevada

Petrographic and geochemical analyses of 50 outcrop samples and 58 drill core samples.

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Cretaceous magmatic rocks of Alaska

Data derived from the 1994 map "Latest Cretaceous and Cenozoic magmatic rocks of Alaska" compiled by E.J. Moll-Stalcup, D.A. Brew, and T.L. Vallier, published (at 1:2,500,000 scale) in volume G-1 of "The Geology of Alaska" (GSA)

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Digital tabulation of stratigraphic data from oil and gas wells in the Santa Maria Basin and surrounding areas, central California coast

This report makes available a large well dataset so that subsurface stratigraphic data are available in digital form for use within a GIS and in construction of three-dimensional models to address regional stratigraphic and structural questions.

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Geochemical database for igneous rocks of the ancestral Cascades Arc--southern segment, California and Nevada

Compilation of all available chemical data (more than 2,000 samples) for igneous rocks that constitute the southern segment of the ancestral Cascades magmatic arc.

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Geochronology and correlation of Tertiary volcanic and intrusive rocks in part of the southern Toquima Range, Nye County, Nevada

40Ar/39Ar dating, electron microprobe analyses and geologic mapping help clarify chronology and correlations of the numerous volcanic and intrusive units exposed in the area and interpret the petrogenesis of a few of the volcanic units.

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Geochronology and geology of late Oligocene through Miocene volcanism and mineralization in the western San Juan mountains, Colorado

New age determinations with descriptions of sample locations and analytical details.

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Gravity survey and interpretation of Fort Irwin and vicinity, Mojave Desert, California

Provides a view of alluvial basins, shapes, areal extents, and approximate thicknesses of alluvial fill. Gravity field is separated into density variations in the basement complex and distribution of Cenozoic fill with its 3-D thickness representation.

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Mineralogic causes of variations in magnetic susceptibility of late Pleistocene and Holocene sediment from Great Salt Lake, Utah

Results of magnetic susceptibility (MS) measurements and magnetic mineralogy of sediments sampled in three cores from the south basin of Great Salt Lake

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Stratabound copper-silver deposits of the Mesoproterozoic Revett Formation, Montana and Idaho with a section on databases and spatial-data files for the geology and mineral deposits of the Revett Formation

Includes deposits, occurrences, and prospects; drill core logs and measured sections; and spatial databases for geologic maps, untested exploration areas, and permissive tracts for undiscovered mineral deposits.

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